xref: /freebsd/sys/x86/isa/isa_dma.c (revision b740c88bfb6453416926271c089262e7164dace3)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	from: @(#)isa.c	7.2 (Berkeley) 5/13/91
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 /*
39  * code to manage AT bus
40  *
41  * 92/08/18  Frank P. MacLachlan (fpm@crash.cts.com):
42  * Fixed uninitialized variable problem and added code to deal
43  * with DMA page boundaries in isa_dmarangecheck().  Fixed word
44  * mode DMA count compution and reorganized DMA setup code in
45  * isa_dmastart()
46  */
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/bus.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/lock.h>
54 #include <sys/proc.h>
55 #include <sys/mutex.h>
56 #include <sys/module.h>
57 #include <vm/vm.h>
58 #include <vm/vm_param.h>
59 #include <vm/pmap.h>
60 #include <isa/isareg.h>
61 #include <isa/isavar.h>
62 #include <isa/isa_dmareg.h>
63 
64 #define	ISARAM_END	0x1000000
65 
66 static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
67 
68 static caddr_t	dma_bouncebuf[8];
69 static u_int	dma_bouncebufsize[8];
70 static u_int8_t	dma_bounced = 0;
71 static u_int8_t	dma_busy = 0;		/* Used in isa_dmastart() */
72 static u_int8_t	dma_inuse = 0;		/* User for acquire/release */
73 static u_int8_t dma_auto_mode = 0;
74 static struct mtx isa_dma_lock;
75 MTX_SYSINIT(isa_dma_lock, &isa_dma_lock, "isa DMA lock", MTX_DEF);
76 
77 #define VALID_DMA_MASK (7)
78 
79 /* high byte of address is stored in this port for i-th dma channel */
80 static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
81 
82 /*
83  * Setup a DMA channel's bounce buffer.
84  */
85 int
86 isa_dma_init(int chan, u_int bouncebufsize, int flag)
87 {
88 	void *buf;
89 	int contig;
90 
91 #ifdef DIAGNOSTIC
92 	if (chan & ~VALID_DMA_MASK)
93 		panic("isa_dma_init: channel out of range");
94 #endif
95 
96 
97 	/* Try malloc() first.  It works better if it works. */
98 	buf = malloc(bouncebufsize, M_DEVBUF, flag);
99 	if (buf != NULL) {
100 		if (isa_dmarangecheck(buf, bouncebufsize, chan) != 0) {
101 			free(buf, M_DEVBUF);
102 			buf = NULL;
103 		}
104 		contig = 0;
105 	}
106 
107 	if (buf == NULL) {
108 		buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful,
109 			   1ul, chan & 4 ? 0x20000ul : 0x10000ul);
110 		contig = 1;
111 	}
112 
113 	if (buf == NULL)
114 		return (ENOMEM);
115 
116 	mtx_lock(&isa_dma_lock);
117 	/*
118 	 * If a DMA channel is shared, both drivers have to call isa_dma_init
119 	 * since they don't know that the other driver will do it.
120 	 * Just return if we're already set up good.
121 	 * XXX: this only works if they agree on the bouncebuf size.  This
122 	 * XXX: is typically the case since they are multiple instances of
123 	 * XXX: the same driver.
124 	 */
125 	if (dma_bouncebuf[chan] != NULL) {
126 		if (contig)
127 			contigfree(buf, bouncebufsize, M_DEVBUF);
128 		else
129 			free(buf, M_DEVBUF);
130 		mtx_unlock(&isa_dma_lock);
131 		return (0);
132 	}
133 
134 	dma_bouncebufsize[chan] = bouncebufsize;
135 	dma_bouncebuf[chan] = buf;
136 
137 	mtx_unlock(&isa_dma_lock);
138 
139 	return (0);
140 }
141 
142 /*
143  * Register a DMA channel's usage.  Usually called from a device driver
144  * in open() or during its initialization.
145  */
146 int
147 isa_dma_acquire(chan)
148 	int chan;
149 {
150 #ifdef DIAGNOSTIC
151 	if (chan & ~VALID_DMA_MASK)
152 		panic("isa_dma_acquire: channel out of range");
153 #endif
154 
155 	mtx_lock(&isa_dma_lock);
156 	if (dma_inuse & (1 << chan)) {
157 		printf("isa_dma_acquire: channel %d already in use\n", chan);
158 		mtx_unlock(&isa_dma_lock);
159 		return (EBUSY);
160 	}
161 	dma_inuse |= (1 << chan);
162 	dma_auto_mode &= ~(1 << chan);
163 	mtx_unlock(&isa_dma_lock);
164 
165 	return (0);
166 }
167 
168 /*
169  * Unregister a DMA channel's usage.  Usually called from a device driver
170  * during close() or during its shutdown.
171  */
172 void
173 isa_dma_release(chan)
174 	int chan;
175 {
176 #ifdef DIAGNOSTIC
177 	if (chan & ~VALID_DMA_MASK)
178 		panic("isa_dma_release: channel out of range");
179 
180 	mtx_lock(&isa_dma_lock);
181 	if ((dma_inuse & (1 << chan)) == 0)
182 		printf("isa_dma_release: channel %d not in use\n", chan);
183 #else
184 	mtx_lock(&isa_dma_lock);
185 #endif
186 
187 	if (dma_busy & (1 << chan)) {
188 		dma_busy &= ~(1 << chan);
189 		/*
190 		 * XXX We should also do "dma_bounced &= (1 << chan);"
191 		 * because we are acting on behalf of isa_dmadone() which
192 		 * was not called to end the last DMA operation.  This does
193 		 * not matter now, but it may in the future.
194 		 */
195 	}
196 
197 	dma_inuse &= ~(1 << chan);
198 	dma_auto_mode &= ~(1 << chan);
199 
200 	mtx_unlock(&isa_dma_lock);
201 }
202 
203 /*
204  * isa_dmacascade(): program 8237 DMA controller channel to accept
205  * external dma control by a board.
206  */
207 void
208 isa_dmacascade(chan)
209 	int chan;
210 {
211 #ifdef DIAGNOSTIC
212 	if (chan & ~VALID_DMA_MASK)
213 		panic("isa_dmacascade: channel out of range");
214 #endif
215 
216 	mtx_lock(&isa_dma_lock);
217 	/* set dma channel mode, and set dma channel mode */
218 	if ((chan & 4) == 0) {
219 		outb(DMA1_MODE, DMA37MD_CASCADE | chan);
220 		outb(DMA1_SMSK, chan);
221 	} else {
222 		outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
223 		outb(DMA2_SMSK, chan & 3);
224 	}
225 	mtx_unlock(&isa_dma_lock);
226 }
227 
228 /*
229  * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
230  * problems by using a bounce buffer.
231  */
232 void
233 isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
234 {
235 	vm_paddr_t phys;
236 	int waport;
237 	caddr_t newaddr;
238 	int dma_range_checked;
239 
240 	dma_range_checked = isa_dmarangecheck(addr, nbytes, chan);
241 
242 #ifdef DIAGNOSTIC
243 	if (chan & ~VALID_DMA_MASK)
244 		panic("isa_dmastart: channel out of range");
245 
246 	if ((chan < 4 && nbytes > (1<<16))
247 	    || (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))
248 		panic("isa_dmastart: impossible request");
249 
250 	mtx_lock(&isa_dma_lock);
251 	if ((dma_inuse & (1 << chan)) == 0)
252 		printf("isa_dmastart: channel %d not acquired\n", chan);
253 #else
254 	mtx_lock(&isa_dma_lock);
255 #endif
256 
257 #if 0
258 	/*
259 	 * XXX This should be checked, but drivers like ad1848 only call
260 	 * isa_dmastart() once because they use Auto DMA mode.  If we
261 	 * leave this in, drivers that do this will print this continuously.
262 	 */
263 	if (dma_busy & (1 << chan))
264 		printf("isa_dmastart: channel %d busy\n", chan);
265 #endif
266 
267 	dma_busy |= (1 << chan);
268 
269 	if (dma_range_checked) {
270 		if (dma_bouncebuf[chan] == NULL
271 		    || dma_bouncebufsize[chan] < nbytes)
272 			panic("isa_dmastart: bad bounce buffer");
273 		dma_bounced |= (1 << chan);
274 		newaddr = dma_bouncebuf[chan];
275 
276 		/* copy bounce buffer on write */
277 		if (!(flags & ISADMA_READ))
278 			bcopy(addr, newaddr, nbytes);
279 		addr = newaddr;
280 	}
281 
282 	/* translate to physical */
283 	phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
284 
285 	if (flags & ISADMA_RAW) {
286 	    dma_auto_mode |= (1 << chan);
287 	} else {
288 	    dma_auto_mode &= ~(1 << chan);
289 	}
290 
291 	if ((chan & 4) == 0) {
292 		/*
293 		 * Program one of DMA channels 0..3.  These are
294 		 * byte mode channels.
295 		 */
296 		/* set dma channel mode, and reset address ff */
297 
298 		/* If ISADMA_RAW flag is set, then use autoinitialise mode */
299 		if (flags & ISADMA_RAW) {
300 		  if (flags & ISADMA_READ)
301 			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
302 		  else
303 			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
304 		}
305 		else
306 		if (flags & ISADMA_READ)
307 			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
308 		else
309 			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
310 		outb(DMA1_FFC, 0);
311 
312 		/* send start address */
313 		waport =  DMA1_CHN(chan);
314 		outb(waport, phys);
315 		outb(waport, phys>>8);
316 		outb(dmapageport[chan], phys>>16);
317 
318 		/* send count */
319 		outb(waport + 1, --nbytes);
320 		outb(waport + 1, nbytes>>8);
321 
322 		/* unmask channel */
323 		outb(DMA1_SMSK, chan);
324 	} else {
325 		/*
326 		 * Program one of DMA channels 4..7.  These are
327 		 * word mode channels.
328 		 */
329 		/* set dma channel mode, and reset address ff */
330 
331 		/* If ISADMA_RAW flag is set, then use autoinitialise mode */
332 		if (flags & ISADMA_RAW) {
333 		  if (flags & ISADMA_READ)
334 			outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
335 		  else
336 			outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
337 		}
338 		else
339 		if (flags & ISADMA_READ)
340 			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
341 		else
342 			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
343 		outb(DMA2_FFC, 0);
344 
345 		/* send start address */
346 		waport = DMA2_CHN(chan - 4);
347 		outb(waport, phys>>1);
348 		outb(waport, phys>>9);
349 		outb(dmapageport[chan], phys>>16);
350 
351 		/* send count */
352 		nbytes >>= 1;
353 		outb(waport + 2, --nbytes);
354 		outb(waport + 2, nbytes>>8);
355 
356 		/* unmask channel */
357 		outb(DMA2_SMSK, chan & 3);
358 	}
359 	mtx_unlock(&isa_dma_lock);
360 }
361 
362 void
363 isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
364 {
365 #ifdef DIAGNOSTIC
366 	if (chan & ~VALID_DMA_MASK)
367 		panic("isa_dmadone: channel out of range");
368 
369 	if ((dma_inuse & (1 << chan)) == 0)
370 		printf("isa_dmadone: channel %d not acquired\n", chan);
371 #endif
372 
373 	mtx_lock(&isa_dma_lock);
374 	if (((dma_busy & (1 << chan)) == 0) &&
375 	    (dma_auto_mode & (1 << chan)) == 0 )
376 		printf("isa_dmadone: channel %d not busy\n", chan);
377 
378 	if ((dma_auto_mode & (1 << chan)) == 0)
379 		outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
380 
381 	if (dma_bounced & (1 << chan)) {
382 		/* copy bounce buffer on read */
383 		if (flags & ISADMA_READ)
384 			bcopy(dma_bouncebuf[chan], addr, nbytes);
385 
386 		dma_bounced &= ~(1 << chan);
387 	}
388 	dma_busy &= ~(1 << chan);
389 	mtx_unlock(&isa_dma_lock);
390 }
391 
392 /*
393  * Check for problems with the address range of a DMA transfer
394  * (non-contiguous physical pages, outside of bus address space,
395  * crossing DMA page boundaries).
396  * Return true if special handling needed.
397  */
398 
399 static int
400 isa_dmarangecheck(caddr_t va, u_int length, int chan)
401 {
402 	vm_paddr_t phys, priorpage = 0;
403 	vm_offset_t endva;
404 	u_int dma_pgmsk = (chan & 4) ?  ~(128*1024-1) : ~(64*1024-1);
405 
406 	endva = (vm_offset_t)round_page((vm_offset_t)va + length);
407 	for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
408 		phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
409 		if (phys == 0)
410 			panic("isa_dmacheck: no physical page present");
411 		if (phys >= ISARAM_END)
412 			return (1);
413 		if (priorpage) {
414 			if (priorpage + PAGE_SIZE != phys)
415 				return (1);
416 			/* check if crossing a DMA page boundary */
417 			if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
418 				return (1);
419 		}
420 		priorpage = phys;
421 	}
422 	return (0);
423 }
424 
425 /*
426  * Query the progress of a transfer on a DMA channel.
427  *
428  * To avoid having to interrupt a transfer in progress, we sample
429  * each of the high and low databytes twice, and apply the following
430  * logic to determine the correct count.
431  *
432  * Reads are performed with interrupts disabled, thus it is to be
433  * expected that the time between reads is very small.  At most
434  * one rollover in the low count byte can be expected within the
435  * four reads that are performed.
436  *
437  * There are three gaps in which a rollover can occur :
438  *
439  * - read low1
440  *              gap1
441  * - read high1
442  *              gap2
443  * - read low2
444  *              gap3
445  * - read high2
446  *
447  * If a rollover occurs in gap1 or gap2, the low2 value will be
448  * greater than the low1 value.  In this case, low2 and high2 are a
449  * corresponding pair.
450  *
451  * In any other case, low1 and high1 can be considered to be correct.
452  *
453  * The function returns the number of bytes remaining in the transfer,
454  * or -1 if the channel requested is not active.
455  *
456  */
457 static int
458 isa_dmastatus_locked(int chan)
459 {
460 	u_long	cnt = 0;
461 	int	ffport, waport;
462 	u_long	low1, high1, low2, high2;
463 
464 	mtx_assert(&isa_dma_lock, MA_OWNED);
465 
466 	/* channel active? */
467 	if ((dma_inuse & (1 << chan)) == 0) {
468 		printf("isa_dmastatus: channel %d not active\n", chan);
469 		return(-1);
470 	}
471 	/* channel busy? */
472 
473 	if (((dma_busy & (1 << chan)) == 0) &&
474 	    (dma_auto_mode & (1 << chan)) == 0 ) {
475 	    printf("chan %d not busy\n", chan);
476 	    return -2 ;
477 	}
478 	if (chan < 4) {			/* low DMA controller */
479 		ffport = DMA1_FFC;
480 		waport = DMA1_CHN(chan) + 1;
481 	} else {			/* high DMA controller */
482 		ffport = DMA2_FFC;
483 		waport = DMA2_CHN(chan - 4) + 2;
484 	}
485 
486 	disable_intr();			/* no interrupts Mr Jones! */
487 	outb(ffport, 0);		/* clear register LSB flipflop */
488 	low1 = inb(waport);
489 	high1 = inb(waport);
490 	outb(ffport, 0);		/* clear again */
491 	low2 = inb(waport);
492 	high2 = inb(waport);
493 	enable_intr();			/* enable interrupts again */
494 
495 	/*
496 	 * Now decide if a wrap has tried to skew our results.
497 	 * Note that after TC, the count will read 0xffff, while we want
498 	 * to return zero, so we add and then mask to compensate.
499 	 */
500 	if (low1 >= low2) {
501 		cnt = (low1 + (high1 << 8) + 1) & 0xffff;
502 	} else {
503 		cnt = (low2 + (high2 << 8) + 1) & 0xffff;
504 	}
505 
506 	if (chan >= 4)			/* high channels move words */
507 		cnt *= 2;
508 	return(cnt);
509 }
510 
511 int
512 isa_dmastatus(int chan)
513 {
514 	int status;
515 
516 	mtx_lock(&isa_dma_lock);
517 	status = isa_dmastatus_locked(chan);
518 	mtx_unlock(&isa_dma_lock);
519 
520 	return (status);
521 }
522 
523 /*
524  * Reached terminal count yet ?
525  */
526 int
527 isa_dmatc(int chan)
528 {
529 
530 	if (chan < 4)
531 		return(inb(DMA1_STATUS) & (1 << chan));
532 	else
533 		return(inb(DMA2_STATUS) & (1 << (chan & 3)));
534 }
535 
536 /*
537  * Stop a DMA transfer currently in progress.
538  */
539 int
540 isa_dmastop(int chan)
541 {
542 	int status;
543 
544 	mtx_lock(&isa_dma_lock);
545 	if ((dma_inuse & (1 << chan)) == 0)
546 		printf("isa_dmastop: channel %d not acquired\n", chan);
547 
548 	if (((dma_busy & (1 << chan)) == 0) &&
549 	    ((dma_auto_mode & (1 << chan)) == 0)) {
550 		printf("chan %d not busy\n", chan);
551 		mtx_unlock(&isa_dma_lock);
552 		return -2 ;
553 	}
554 
555 	if ((chan & 4) == 0) {
556 		outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
557 	} else {
558 		outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
559 	}
560 
561 	status = isa_dmastatus_locked(chan);
562 
563 	mtx_unlock(&isa_dma_lock);
564 
565 	return (status);
566 }
567 
568 /*
569  * Attach to the ISA PnP descriptor for the AT DMA controller
570  */
571 static struct isa_pnp_id atdma_ids[] = {
572 	{ 0x0002d041 /* PNP0200 */, "AT DMA controller" },
573 	{ 0 }
574 };
575 
576 static int
577 atdma_probe(device_t dev)
578 {
579 	int result;
580 
581 	if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
582 		device_quiet(dev);
583 	return(result);
584 }
585 
586 static int
587 atdma_attach(device_t dev)
588 {
589 	return(0);
590 }
591 
592 static device_method_t atdma_methods[] = {
593 	/* Device interface */
594 	DEVMETHOD(device_probe,		atdma_probe),
595 	DEVMETHOD(device_attach,	atdma_attach),
596 	DEVMETHOD(device_detach,	bus_generic_detach),
597 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
598 	DEVMETHOD(device_suspend,	bus_generic_suspend),
599 	DEVMETHOD(device_resume,	bus_generic_resume),
600 	{ 0, 0 }
601 };
602 
603 static driver_t atdma_driver = {
604 	"atdma",
605 	atdma_methods,
606 	1,		/* no softc */
607 };
608 
609 static devclass_t atdma_devclass;
610 
611 DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
612 DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);
613